>> reporter: scott, that medication is supposed to be prepared nay sterile environment but if there's a breakdown in the system there could be contamination in the fungus. it's common in soil, decomposing leaves and even floating in the air. >> pelley: if the fungus is everywhere, as you describe it, why is it so dangerous in this case? >> reporter: in somebody with a normal immune system the lungs filter it out. when you inject it directly into the spine, that's like a straight highway to the brain. >> pelley: jon, thank you very much. it has been more than three weeks since that deadly terrorist attack on the u.s. consulate in benghazi, libya. today, the will bean government finally allowed a team of f.b.i. agents to see the crime scene. four americans were killed in that attack, of course, including ambassador chris stephens. the agents, with a u.s. military escort, spent 12 hours at the consulate, though much of the evidence has already been compromised there. the violence in syria's civil war is spilling over its borders. for a second day, turkey fired artillery shells into syria